A face protection mask, a method for producing face protection masks and an apparatus for producing face protection masks

ABSTRACT

A method and apparatus for producing face protection masks including a non-woven fabric mask body and at least one elastic band parallel to the longitudinal axis of the mask body and including at least one elastic element fixed between two layers of non-woven fabric.

FIELD OF THE INVENTION

The present invention relates to a face protection mask and a method and an apparatus for producing face protection masks.

The invention has been developed with particular regard to producing disposable surgical masks, however, the invention can also be used for producing face protection masks of other types, such as masks having a mask body to which at least one elastic element is fixed for its use.

DESCRIPTION OF THE PRIOR ART

A widely used type of disposable surgical mask comprises a mask body, typically formed of a multilayer rectangular panel of non-woven fabric with a series of parallel folds, and two C-shaped elastic threads attached to opposite sides of the mask body, which form two loops for the ears that are placed around the users ears to hold the mask body in position in front of the users mouth and nose. Further known embodiments envisage the mask body being connected to elastic bands which—in use—are arranged around the back of the head and/or around the back of the neck.

Most of the known apparatuses for producing masks of this type envisage stopping the mask bodies for applying the elastic loops for the ears in semi-automatic or manual mode. These apparatuses typically have a production speed in the order of 50 pieces/minute in manual mode and can reach speeds in the order of 175 pieces/minute in semi-automatic mode.

These production speeds are largely insufficient for articles of this kind, especially when compared with the production speeds of the most modern machines for producing disposable sanitary articles, for example, absorbent sanitary articles, which reach production speeds in the order of 800-1000 pieces/minute.

Another problem of the face protection masks according to the prior art is the difficulty of supplying the elastic threads used for producing the elastic loops for the ears.

Another problem of the known solutions is that it is not possible to quickly and efficiently produce masks having elastic threads with different elastic properties.

It is known that the elastic properties of elastic threads are fixed and depend mainly on the raw material and the geometry used. This implies that known solutions are scarcely flexible.

The known solutions typically only allow production of one type of mask having elastic threads with predefined characteristics on which it is not possible to intervene to produce different batches of masks.

If it is intended to obtain batches of masks with different elastic properties, it is necessary to replace the raw material of the elastic threads and possibly make multiple changes to the apparatus for producing the masks.

OBJECT AND SUMMARY OF THE INVENTION

The present invention aims to provide a face protection mask that can be produced with higher speeds than the face protection masks according to the prior art and that is not affected by problems of finding raw materials.

In particular, the invention has the object of making face protection masks by processing the elastic bands directly in line, adapting the specific elastic characteristics according to the specific batch to be made each time.

This increases production flexibility as it is possible to manage the elastic bands to be coupled to the masks directly in line and in the required manner.

According to another aspect, the invention relates to a method and an apparatus for producing face protection masks that overcome the problems of the prior art.

In particular, the object of the present invention is to provide a method and an apparatus for producing face protection masks, which have production speeds that are considerably higher than those of the apparatuses currently available on the market.

According to another aspect, the invention relates to a method and an apparatus for producing face protection masks that overcome the problems of the prior art.

In accordance with possible embodiments, the present invention relates to a face protection mask comprising a mask body having a longitudinal axis and two side edges, and at least one elastic band parallel to the longitudinal axis and having opposite ends fixed to the respective side edges of the mask body, wherein the at least one elastic band comprises at least one elastic element trapped between two layers of non-woven fabric.

According to possible embodiments, the mask body may comprise a non-woven fabric. For example, the mask body may comprise a multilayer of non-woven fabrics optionally where there are one or more additional layers of functional materials such as filter materials.

Thanks to the type of elastic band thus formed, it is possible to create multiple types of elastic bands having the most varied and diversified elastic properties each time.

According to possible embodiments, in an extended condition of the mask body the at least one elastic band is in a tension-free state.

This aspect makes it possible to have a face protection mask that, when not in use, does not have any bending due to the residual tension of the elastic bands that typically occurs in known methods, be they manual or semi-automatic, or even automatic.

In accordance with possible embodiments, at least one elastic band comprises a plurality of elastic threads.

This aspect makes it possible to modify the elastic properties of the elastic bands as a function of the number of elastic threads, their diameter, their intrinsic elastic properties, the mutual distance, the tension they individually have when they are trapped between the two layers of non-woven fabric and their position along the elastic band which, for example, may be linear, wavy, curved or of another type. A preferred variant envisages that the elastic threads are parallel to each other.

According to possible embodiments, at least one elastic band has the two layers of non-woven fabric welded together by means of a plurality of anchor welds. Each anchor weld comprises a pair of welds placed on the sides of one of the elastic threads and spaced apart by a length less than the diameter of said elastic thread at rest, so as to trap the latter between the two layers of non-woven fabric.

Diameter means the average diameter that the elastic thread has at rest, or in the case of several threads wound or intertwined with each other, it means the maximum equivalent diameter of the elastic thread assembly.

This aspect allows the elastic threads to be trapped without the aid of glue, and also allows obtainment of elastic bands with uniform and separate pleating of the required pitch.

In accordance with possible embodiments, at least one elastic band comprises a laminar elastic element.

The laminar elastic element can be a web having a width substantially equal to that of the two layers of non-woven fabric.

The elastic band may also comprise a plurality of laminar elastic elements, for example, they may comprise a plurality of elastic bands parallel to each other.

These embodiments allow obtainment of an elastic band with required elastic properties. In addition, thanks to the flattened shape of the laminar elastic element, which—in use—rests on the back of the head or neck, the elastic band is more ergonomic.

According to possible embodiments, the laminar elastic element comprises a plurality of holes through which the two layers of non-woven fabric are welded together.

This aspect allows increasing the already high breathability of the elastic bands as the holes in the laminar elastic element allow a greater passage of air.

In accordance with possible embodiments, at least one end of the at least one elastic band is fixed to a side edge of the mask body by means of an attachment area having an inclined extension with respect to the longitudinal axis.

Thanks to the inclination of the attachment areas of the elastic band, the fit of the mask is significantly improved as the mask body adheres better to the users face at the side edges where the elastic band is welded.

According to possible embodiments, the face protection mask comprises two elastic bands adjacent to respective longitudinal edges of the mask body and having respective opposite ends fixed to the mask body along respective attachment areas.

This aspect allows a more stable mask in position during use as the two adjacent elastic bands keep the mask body in position, preventing it from moving from the required position. For example, this configuration prevents the nose from being uncovered during the use of the mask while the user speaks, or moves his mouth.

In accordance with possible embodiments, an elastic band has a longitudinal extension at rest that is different from that of another elastic band.

According to possible embodiments, an elastic band is configured to extend elastically up to a maximum longitudinal extension different from that of another elastic band. By elastic extension, it is meant that the elastic band, once extended, returns to the rest configuration without having undergone a plastic deformation greater than 10% of the length of the elastic band in the rest configuration.

Both aspects relating to the diversification between some characteristics between the two elastic bands, whether they are considered together or taken individually, allow masks to be produced with different elastic properties that are not achievable with the known solutions.

In accordance with possible embodiments, the attachment areas of a lower elastic band have a greater extension in the longitudinal direction than the extension in the longitudinal direction of the attachment areas of an upper elastic band.

This aspect allows obtaining a reduction of the neckline of the lower elastic band to the advantage of a better fit of the mask.

According to possible embodiments, the layers of non-woven fabric of an elastic band are formed by a single sheet of non-woven fabric folded along a longitudinal line.

This aspect is advantageous since it is not necessary to manage two sheets of non-woven fabric by means of two separate unwinders trying to coordinate them so that the two sheets remain perfectly overlapped. According to this embodiment, it is possible to use a single unwinder for the sheet of non-woven fabric that is folded.

In accordance with possible embodiments, at least one of the layers of non-woven fabric is fastened to the mask body in a removable way.

This aspect is advantageous above all during the making of the masks since once the layer of non-woven fabric has been attached to the mask body it does not move, and simplifies the subsequent processing along the production line.

This aspect also makes it possible to prevent the elastic bands from colliding with or getting entangled in the processing units during movement along the production line.

The same considerations are also valid during the packaging step, since it is advantageous for the elastic bands to remain in position on the mask body.

To wear these masks, the user only has to break the connection that can be made, for example, by means of technical welds typical in the sector of absorbent hygienic items.

According to possible embodiments, the present invention relates to a face protection mask that comprises a mask body having a longitudinal axis and two side edges, and at least one elastic band parallel to the longitudinal axis, and having opposite ends fixed to respective side edges of the mask body, wherein—in an extended condition of the mask body—the at least one elastic band is in a tension-free state.

This allows the mask to be maintained without the elastic band exerting a pulling action that bends the mask.

According to possible embodiments, the at least one elastic band comprises at least one elastic element fixed between two layers of non-woven fabric.

This aspect allows production of masks having elastic bands with required elastic properties directly in line.

In other words, it is possible to adjust the elasticity of the elastic bands in relation to how the elastic band is made directly in line, and this is decidedly advantageous with respect to known solutions wherein the elastic properties of the elastic bands are predetermined by the material and shape with which they are provided, without the possibility of modifying them according to the specific needs.

In accordance with possible embodiments, in an extended condition of the mask body, the layers of non-woven fabric are pleated.

This aspect makes the elastic bands more ergonomic since—in contact with the body—they are softer and also allow greater transpiration of the head and neck compared to known solutions.

In accordance with possible embodiments, the present invention also relates to a method for producing face protection masks, comprising:

-   -   forming a succession of mask bodies each having a longitudinal         axis and two side edges,     -   forming a succession of elastic bands, each comprising at least         one elastic element trapped between two layers of non-woven         fabric,     -   attaching opposite ends of each of the elastic bands to         respective side edges of a respective mask body.

This aspect makes it possible to manage the production of the elastic bands directly in line, adapting their characteristics in relation to specific needs.

According to possible embodiments, the method envisages that the elastic bands are fixed to respective mask bodies in a tension-free state.

This allows the mask bodies to be manipulated and conveyed with the elastic bands, without the need to consider any curvature of the mask due to some residual tension of the elastic bands.

In accordance with possible embodiments, the method envisages that the elastic bands are fixed to respective mask bodies while the elastic bands advance in a machine direction at a speed greater than the feed rate of the mask bodies in the same machine direction.

This allows attaching of the bands by reducing any residual tension and also allows attaching, again without residual tension, elastic bands longer than the longitudinal extension of the mask bodies.

According to possible embodiments, the method envisages that two elastic bands parallel to each other are fixed to each mask body.

In accordance with possible embodiments, the method envisages that the lower elastic bands are attached to respective mask bodies at attachment areas having an extension in the longitudinal direction greater than the extension in the longitudinal direction of the attachment areas of the upper elastic bands.

According to possible embodiments, the method comprises:

-   -   forming a continuous sheet having a longitudinal axis,     -   forming at least one continuous elastic band comprising a         continuous elastic element trapped between two continuous layers         of non-woven fabric,     -   overlapping at least one continuous elastic band and the         continuous sheet, with the continuous elastic band parallel to         the longitudinal axis,     -   attaching together the continuous sheet and the at least one         continuous elastic band along attachment areas, and     -   cutting the continuous sheet and the at least one continuous         elastic band along cutting lines.

According to possible embodiments, the continuous sheet may comprise a non-woven fabric. According to possible embodiments, the continuous sheet may comprise a multilayer of non-woven fabric possibly in which there are one or more additional layers of functional materials such as filtering materials.

According to possible embodiments, the method envisages that the formation of the continuous elastic band envisages applying at least one continuous elastic element on a longitudinal portion of a single sheet of non-woven fabric, and folding the single sheet of non-woven fabric along a longitudinal line so as to trap the at least one continuous elastic element between two superimposed longitudinal portions, wherein the superimposed portions correspond to the two continuous layers of non-woven fabric.

In accordance with possible embodiments, the method envisages that the continuous elastic element is fixed between two layers of smooth non-woven fabric in a state stretched in the longitudinal direction, and wherein the continuous elastic band is slowed down before being attached to the continuous sheet of non-woven fabric.

According to possible embodiments, the method envisages that the continuous elastic element is fixed between two layers of wavy non-woven fabric.

According to possible embodiments, the method envisages that the continuous elastic element is fixed between the layers of wavy non-woven fabric in a non-tensioned state.

This allows obtaining considerably greater extensions than those known today wherein the elastic element is fixed in tension between layers of non-wavy non-woven fabric.

In accordance with possible embodiments, the present invention also relates to a method for producing face protection masks, comprising:

-   -   forming a succession of mask bodies each having a longitudinal         axis and two side edges,     -   forming a succession of elastic bands,     -   attaching opposite ends of each elastic band to respective side         edges of a respective mask body, wherein the elastic bands are         fixed to respective mask bodies in a tension-free state.

In accordance with possible embodiments, the method envisages that the elastic bands are pleated when they are fixed to the respective mask bodies.

According to possible embodiments, the method comprises:

-   -   forming a continuous sheet having a longitudinal axis,     -   forming at least one continuous elastic band,     -   overlapping the at least one continuous elastic band and the         continuous sheet, with the continuous elastic band in a         tension-free state,     -   attaching the continuous sheet and the at least one continuous         elastic band together in a tension-free state, and     -   cutting the continuous sheet and the at least one continuous         elastic band along cutting lines.

In accordance with possible embodiments, the present invention also relates to an apparatus for producing face protection masks, comprising:

-   -   a first forming unit configured to form a continuous web         extending along a longitudinal axis,     -   a second forming unit configured to form at least one continuous         elastic band comprising at least one continuous elastic element         trapped between two continuous layers of non-woven fabric,     -   an anvil wheel on which, in use, the at least one continuous         elastic band and the continuous sheet are superimposed on each         other, with the continuous elastic band parallel to the         longitudinal axis,     -   a fastening device configured to cooperate with said anvil wheel         to fasten said continuous sheet and said at least one continuous         elastic band together, and     -   a cutting unit configured for cutting the continuous sheet and         the at least one continuous elastic band along cutting lines.

According to possible embodiments, the apparatus comprises a slowing device arranged between the second forming unit and the anvil wheel and configured to slow down the continuous elastic band upstream of the anvil wheel.

In accordance with possible embodiments, the present invention also relates to an apparatus for producing face protection masks, comprising:

-   -   a first forming unit configured to form a continuous web         extending along a longitudinal axis,     -   a second forming unit configured to form at least one continuous         elastic band,     -   an anvil wheel on which, in use, the at least one continuous         elastic band and said continuous sheet are superimposed on each         other, with the continuous elastic band in a tension-free state,     -   a fastening device configured to cooperate with said anvil wheel         to fasten said continuous sheet and the continuous elastic band         together, and     -   a cutting unit configured for cutting the continuous sheet and         the at least one continuous elastic band along cutting lines.

According to possible embodiments, the anvil wheel is configured to advance the at least one continuous elastic band in a machine direction at a speed greater than the speed of advancement of the continuous non-woven fabric sheet in the same machine direction.

The claims form an integral part of the disclosure provided here in relation to the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described in detail with reference to the attached drawings, given purely by way of non-limiting example, wherein:

FIGS. 1 and 2 are perspective views of an embodiment of a face protection mask according to the present invention,

FIG. 3 is a plan view of the face protection mask of FIGS. 1 and 2 ,

FIG. 4 is a plan view of a second embodiment of a face protection mask according to the present invention,

FIGS. 5 and 6 are plan views of two embodiments of the elastic bands of a mask according to the present invention,

FIG. 7 is a schematic view of an apparatus for producing face protection masks according to the present invention,

FIGS. 8-14 are schematic views illustrating various method steps for producing face protection masks according to the present invention,

FIG. 15 is a schematic side view of an embodiment of an apparatus for forming elastic bands,

FIG. 16 is a schematic perspective view of an elastic band at the outlet of the apparatus in FIG. 15 , and

FIG. 17 is a schematic plan view illustrating an embodiment of a system for forming elastic bands.

It will be appreciated that the various figures may not be represented on the same scale. It will also be appreciated that in some figures certain elements or components may not be illustrated to better highlight others and to simplify the understanding of the figures.

DETAILED DESCRIPTION

A detailed description of the present invention is given below with some variations. This detailed description is exemplary and not limiting, as any further embodiments have also been inserted previously with reference to the synthesis of the invention.

With reference to FIGS. 1-3 , numeral 10 indicates a face protection mask according to an embodiment of the present invention. The mask 10 comprises a mask body 12 and at least one elastic band 14.

In the examples illustrated in the figures, the mask 10 comprises two elastic bands 14, each of which is adjacent to a respective major side of the mask body 12. In use, the two elastic bands 14 are positioned at different heights on the users head to keep the mask body 12 in position in front of the nose and mouth. The upper elastic band 14 is positioned on the nape and the lower elastic band 14 is positioned behind the users neck.

In possible embodiments, the mask 10 may comprise only one elastic band 14. The single elastic band 14 may have a greater width than each of the elastic bands 14 illustrated in FIGS. 1-3 , and can be arranged in a central area of the mask body 12. The single elastic band 14 may have a longitudinal cut that divides the elastic band into two branches that can be arranged at different heights on the users head.

The mask body 12 is formed by one or more layers of non-woven fabric. In an extended position, the mask body 12 has a flat shape elongated along a longitudinal axis A, and has two longitudinal edges 16 and two side edges 18.

In a possible embodiment, the mask body 12 may be constituted by three layers of non-woven fabric superimposed on each other. For example, the inner layer may be made of a Thermal-Bond material, the intermediate layer of a Meltblown material and the outer layer of a Spunbond material.

The mask body 12 has a series of folds 20 parallel to the longitudinal axis A that extend for the entire length of the mask body 12.

The mask body 12 may comprise a nose clip 21 formed by a bar of plastically-deformable material, arranged parallel to the upper longitudinal edge 16 and having the object of shaping the upper edge of the mask body 12 around the users nose. The nose clip 21 may, for example, consist of a thin metal bar coated with a plastic material, for example polyethylene. The nose clip 21 may be held inside a folded longitudinal edge 16 of the mask body 12. The folded longitudinal edge 16 may be attached to the outer face or the inner face of the mask body 12 by ultrasonic welding, glue or thermal welding. In a possible embodiment, both longitudinal edges 16 of the mask body 12 can be folded and fixed to the outer face or the inner face of the mask body 12 by ultrasonic welding, glue or thermal welding.

In the example illustrated in FIG. 1 , the mask body 12 has a rectangular shape wherein the two longitudinal edges 16 are straight and parallel to the longitudinal axis A, and the two side edges 18 are straight and perpendicular to the longitudinal axis A. In this embodiment, the elastic bands 14 have the same length as the mask body 12.

In possible embodiments, the longitudinal edges 16 and/or the transverse edges 18 can be non-straight, and can be shaped in various ways. For example, in the embodiment illustrated in FIG. 4 , the side edges 18 of the mask body 12 may have respective central recessed sections 22, with a C-shape facing outwards. The central recessed portions 22 of the side edges 18 are comprised between the two elastic bands 14. In this embodiment, the elastic bands 14 have a length that is greater than the length of the central part of the mask body 12 comprised between the central recessed portions 22 of the side edges 18.

Each elastic band 14 is parallel to the longitudinal axis A, and may have an outer longitudinal edge parallel and aligned with a corresponding longitudinal edge 16 of the mask body.

The elastic bands 14 have respective opposite ends which are fixed to the mask body 12 along respective attachment areas 24′, 24″ located in the vicinity of the respective side edges 18 of the mask body 12. The attachment of the opposite ends of each elastic band 14 to the mask body 12 may be carried out by means of glue, ultrasonic welding or thermal welding.

With reference to FIGS. 3 and 4 , in a possible embodiment, the attachment areas 24′ of the lower elastic band 14 (the one located along the longitudinal edge 16 opposite to the one bearing the nose clip 21) have an extension in the longitudinal direction greater than the attachment areas 24″ of the upper elastic band 14 (the one located along the longitudinal edge 16 carrying the nose clip 21). In this way, the lower elastic band 14, which in use is positioned on the users neck, has a lower effective length than the upper elastic band 14, which in use is positioned on the users nape and must be lengthened to a greater extent than the lower elastic band 14. In the embodiment illustrated in FIG. 4 , the attachment areas 24′ of the lower elastic band 14 can extend substantially for the entire length of the section of the mask body 12 that extends laterally beyond the recessed part 22.

The elastic bands 14 in addition to being fixed to the mask body 12 in the side attachment areas 24′, 24″ may also be fixed to the mask body 12 in intermediate areas between the side attachment areas 24′, 24″ by means of technical connecting points, for example, by means of technical welding points or by means of technical glue points, which form temporary connecting points intended to be interrupted with a weak release force. In this way, the elastic bands 14 remain adherent to the mask body 12 during production and packaging. The technical connecting points keep the elastic bands 14 neatly in the packaging and before use the technical connecting points can be easily detached.

In a possible embodiment, in an extended configuration of the mask body 12 the elastic bands 14 are in a non-tensioned state. Therefore, in the extended configuration of the mask body 12, the elastic bands 14 do not apply any force to the mask body 12. This prevents the mask body 12 from assuming an arcuate shape at rest. Therefore, at rest, the mask body 12 has a planar configuration, which simplifies the production and packaging operations.

Each elastic band 14 comprises two layers of non-woven fabric 26, and at least one elastic element sandwiched between the two layers of non-woven fabric 26. The elastic element is fixed between the two layers of non-woven fabric 26 by any of the techniques normally used for producing elastic bands in the sector of producing absorbent sanitary articles, for example, by means of glue, ultrasonic welding or thermal welding.

In a possible embodiment, the two layers of non-woven fabric 26 of each elastic band 14 can be formed by a single sheet of non-woven fabric folded along a longitudinal edge.

The layers of non-woven fabric 26 may be of Spunbonded-Meltblown-Spunbonded (SMS) material, or of Thermal Bond material, and may have a grammage measured according to the EDANA NWSP 130.1 regulation between 10 and 20 g/cm², in particular, between 12 and 15 g/cm².

In a possible embodiment, in an extended condition of the mask body 12, the layers of non-woven fabric 26 of the elastic bands 14 can be pleated.

In the embodiment illustrated in FIG. 5 , each elastic band 14 comprises a plurality of elastic threads 28, parallel to each other, fixed to the two layers of non-woven fabric 26 by joining lines 30. The joining lines 30 may have a transverse trend and can be spaced apart from each other in the longitudinal direction.

The joining lines 30 can be formed by welding points that weld the two layers of non-woven fabric 26 together and anchor the elastic threads 28 to the two layers of non-woven fabric 26. The welding points can be spaced apart from each other in a transverse direction by a distance smaller than the diameter of the non-tensioned elastic threads. The elastic threads 28 can be arranged between the two layers of non-woven fabric 26 in a tensioned state and, while the elastic threads 28 are tensioned, the two layers of non-woven fabric 26 are welded together by means of welding points arranged on opposite sides of the tensioned elastic threads 28, and spaced apart from each other by a distance smaller than the diameter of the non-tensioned elastic threads. When the tension of the elastic threads is released, the elastic threads remain anchored to the layers of non-woven fabric 26 at the welding points.

In a possible embodiment, the layers of non-woven fabric 26 may be welded together with a welding pattern comprising anchor welds spaced apart in a transverse direction by a distance less than the diameter of the non-tensioned elastic wires, and welds of containment spaced apart from each other in a transverse direction by a distance greater than the diameter of the non-tensioned elastic threads.

In a possible embodiment, the layers of non-woven fabric 26 can be fixed to each other by means of transverse glue lines spaced apart from each other in the longitudinal direction.

The elastic threads 28 can be made of Lycra® and may have a denier between 480 and 1500 dtex, or between 800 and 1200 dtex.

In the embodiment illustrated in FIG. 6 , each elastic band 14 comprises a laminar elastic element 32 arranged sandwiched between the two layers of non-woven fabric 26, and fixed thereto by means of a plurality of welding points 34, which join together the two layers of non-woven fabric 26 on opposite sides of the laminar elastic element 32. The welding points 34 may form corresponding through-holes 36 through the laminar elastic element 32 that make the elastic band 14 breathable.

The laminar elastic element may consist of an elastic polyolefin film.

With reference to FIG. 7 and FIGS. 8-14 , an apparatus and a method for producing face protection masks 10 of the type described above will now be described.

In FIG. 7 , numeral 40 indicates a continuous flow apparatus for producing face protection masks 10. “Continuous flow apparatus” means an apparatus in which the semi-finished products move continuously without pauses or stops until the finished product is obtained.

The apparatus 40 may comprise a first forming unit 42 configured for the in-line formation of a sheet of multilayer non-woven fabric 44, for example, by overlapping three layers of non-woven fabric 45. Alternatively, the non-woven fabric sheet 44 could be supplied in reels and fed to the apparatus 40 by unwinding devices.

The apparatus 40 comprises a feed unit 46 configured to advance the continuous sheet of non-woven fabric 44 along a machine direction X.

The apparatus 40 comprises a folding device 48 configured to form continuous folds on the continuous moving sheet 44 parallel to the machine direction X. Downstream of the folding device 48, a pressure device 50 can be arranged to compress the continuous sheet 44 on which the continuous longitudinal folds 20 have been formed.

A continuous thread 52 of plastically-deformable material is unwound from a reel 54 and is fed in the machine direction X parallel to a longitudinal side of the continuous fabric 44. A cutting and applying device 56 cuts the continuous thread 52 so as to form a succession of clips for the nose 21, which are applied to the continuous sheet 44 in the vicinity of one of its longitudinal edges. A longitudinal folding device 58 folds the longitudinal edges of the continuous sheet 44. Downstream of the longitudinal folding device 58, a second pressure device 60 can be provided to compress the continuous sheet 44. Then, the continuous sheet 44 passes through an ultrasonic welding device 62, which carries out the ultrasonic welding of the folded longitudinal edges. Alternatively, the apparatus could be equipped with a glue applicator for attaching the folded longitudinal edges with glue or with a thermal welding device.

FIG. 8 illustrates the continuous sheet of non-woven fabric 44 at the outlet of the forming unit 42. FIG. 9 illustrates the continuous sheet of non-woven fabric 44 after the formation of the longitudinal folds 20 and the application of the nose clips 21, and FIG. 10 illustrates the continuous sheet of non-woven fabric 44 after folding and welding of the longitudinal edges 16. The continuous sheet of non-woven fabric 44 in the configuration of FIG. 10 is formed by a continuous succession of mask bodies 12.

With reference to FIG. 7 , the apparatus 40 comprises a second forming unit 64 configured for the in-line formation of at least one continuous elastic band 66. In a possible embodiment, the second forming unit 64 is configured to form two continuous elastic bands 66 parallel to each other.

The second forming unit 64 is configured to enclose at least one continuous elastic element 68 between two continuous layers of non-woven fabric 70. The continuous elastic element 68 can be formed by a plurality of continuous elastic threads parallel to each other or by a film of continuous laminar material. The second forming unit 64 may comprise two applicator rollers 72, which apply the two continuous layers of non-woven fabric 70 on opposite sides of the continuous elastic element 68. The continuous elastic element 68 may be fed to the applicator rollers 72 by means of a feeding device indicated schematically with 74, which can be configured to feed the continuous elastic element 68 in a tensioned state.

The apparatus 40 comprises a fastening device 76 arranged downstream of the second forming unit 64, configured to attach the two continuous layers of non-woven fabric 70 together and anchor the continuous elastic element 68 between the two continuous layers of non-woven-fabric 70. The fastening device 76 may, for example, be formed by an ultrasonic welding apparatus.

In a possible embodiment, the two continuous layers of non-woven fabric 70 of each continuous elastic band 66 may be formed by a single continuous sheet of non-woven fabric folded along a longitudinal edge.

With reference to FIG. 11 , downstream of the fastening device 76 two continuous elastic bands 66 parallel to each other are obtained, each of which comprises an elastic element 68 enclosed between two continuous layers of non-woven fabric 70, wherein the continuous elastic element 68 and the layers of non-woven fabric 70 are attached together along joining lines 30. The joining lines 30, which can be formed by ultrasonic welding spots, can be oriented in the transverse direction and can be spaced apart from each other in the longitudinal direction.

In possible embodiments, the attachment of the elastic element 68 between the two continuous layers of non-woven fabric 70, for example, by means of joining lines 30, to form the continuous elastic bands 66, can be obtained in the ways previously described with reference to FIG. 5 .

With reference to FIG. 7 , the apparatus 40 comprises a slowing device 78 arranged downstream of the fastening device 76, and configured to slow down the continuous elastic bands 66. The slowing device 78 may comprise a roller 80 on which the continuous elastic bands 66 are wound and driven in rotation with a rotation speed such that the peripheral speed of the roller 80 is less than the speed at which the continuous elastic bands 66 are fed to the roller entrance 80. At the outlet of the slowing device 78, the feed rate of the continuous elastic bands 66 is lower than the speed of advancement of the continuous elastic bands 66 upstream of the slowing device 78. During the passage through the slowing device 78 the elastic tension of the continuous elastic elements 68 decreases in proportion to the reduction in the feed rate of the continuous elastic bands 66. The slowing device 78 can be controlled so that the elastic tension of the continuous elastic bands 66 at the outlet of the slowing device 78 has a value close to zero.

With reference to FIG. 12 , the reduction of the tension of the continuous elastic bands 66 causes—at the outlet of the slowing device 78—the layers of non-woven fabric 70 of the continuous elastic bands 66 to assume a pleated or wavy shape. In the configuration of FIG. 12 , the continuous elastic bands 66 are formed by a continuous succession of elastic bands 14 intended to be applied to respective mask bodies 12.

With reference to FIG. 7 , the apparatus 40 comprises a welding unit 82 configured to weld together the continuous sheet of non-woven fabric 44, formed by a continuous succession of mask bodies 12, and the continuous elastic bands 66, formed by a continuous succession of elastic bands 14. The welding unit 82 comprises an anvil wheel 84 rotating around its axis, and an ultrasonic welding device 86 cooperating with the outer surface of the anvil wheel 84. The continuous sheet of non-woven fabric 44 and the continuous elastic bands 66 are fed jointly on the outer surface of the anvil wheel 84 in the machine direction X upstream of the ultrasonic welding device 86 in a superimposed condition, with the elastic bands continuous sheets 66 aligned with the respective longitudinal edges of the continuous sheet of non-woven fabric 44.

With reference to FIG. 13 , the ultrasonic welding unit 82 welds together the continuous elastic bands 66 and the continuous non-woven fabric 44 at regular intervals, and forms attachment areas 24′, 24″ between the elastic bands 14 and the respective mask bodies 12. The ultrasonic welding unit 82 can also carry out the transversal welding of the continuous sheet of non-woven fabric 44 in the section between the two elastic bands 66 to form the welding of the side edges 18 of the mask bodies 12. As shown in FIG. 13 , the attachment areas 24′ of the lower elastic bands 14 may have an extension in the longitudinal direction that is greater than the extension in the longitudinal direction of the attachment areas 24″ between the upper elastic bands 14.

According to a characteristic of the present invention, the ultrasonic welding unit 82 is configured to attach the elastic bands 14 to the respective mask bodies 12 with a complete absence of elastic tension of the elastic bands 14. According to an embodiment of the present invention, the cancellation of the elastic tension of the continuous elastic bands 66 is obtained by advancing the continuous elastic bands 66 upstream of the ultrasonic welding device 86 at a speed greater than the feed rate of the mask bodies 12. The difference between the feed rate of the continuous elastic bands 66 and that of the mask bodies 12 may be obtained by holding the continuous elastic bands 66 in contact with the outer surface of the anvil wheel 84, and by driving the anvil wheel 84 in rotation with a rotation speed such that the peripheral speed of the anvil wheel 84 is greater than the speed of advancement in the machine direction X of the continuous web of non-woven fabric 44.

Since the continuous elastic bands 66 downstream of the slowing device 78 are almost free of elastic tension, it is advisable for the continuous elastic bands 66 to be supported and guided in the path between the slowing device 78 and the anvil wheel 84. For this object, the apparatus 40 may comprise one or more conveyors 88 arranged between the slowing device 78 and the anvil wheel 84, and configured to guide the continuous elastic bands 66 towards the outer surface of the anvil wheel 84. Each of the conveyors 88 may comprise two closed-loop conveyor belts that tighten the elastic bands 66 together.

With reference to FIG. 13 , at the outlet of the welding unit 82, a continuous composite sheet is obtained formed by a succession of finished masks 10 joined together.

With reference to FIG. 7 , the apparatus 40 includes a cutting unit 90 configured to cut the continuous composite sheet to separate the finished individual masks 10 from each other. The cutting unit 90 cuts the continuous elastic bands 66 and the continuous non-woven fabric sheet 44 along cutting lines indicated by 92 in FIG. 13 . At the outlet of the cutting unit 90, individual masks 10 are obtained having the shape shown in FIG. 14 .

To form the masks 10 according to the embodiment illustrated in FIG. 4 , the cutting unit 90 makes the cut along a cutting path including two straight portions at the elastic bands 66 and a closed loop path at the continuous sheet of non-woven fabric 44 between the two elastic bands 66. In this way, a scrap is formed with a shape corresponding to that of the closed-loop cutting path between each pair of masks 10 adjacent to each other. The scraps can be evacuated by means of a suction device.

In possible embodiments, the continuous sheet of non-woven fabric 44 can be cut to form individual mask bodies 12 upstream of the welding unit 82. The continuous elastic bands 66 may be cut so as to form individual elastic bands 14 upstream or downstream of the welding device 86.

FIG. 15 schematically illustrates a second embodiment of a unit 64 for forming elastic bands 66. The forming unit 64 comprises a pair of gears 94 cooperating with each other. Each of the gears 94 cooperates in turn with an additional gear 96. Two continuous sheets of non-woven fabric 70 are passed between each pair of wheels 94, 96. The toothed wheels 94, 96 impart a wavy shape to the respective sheets of non-woven fabric 70. A continuous elastic element 68 is fed by a feeding device 74 between the two gears 94, and is enclosed between the two corrugated sheets of non-woven fabric 70. The continuous elastic element 68 can be formed by a plurality of elastic threads 28 parallel to each other, as shown in FIG. 16 , or by a laminar film. At the outlet of the forming unit 64, the two wavy non-woven fabric sheets 70 are fixed together by welding or glue to anchor the elastic element 68 between the two wavy non-woven fabric sheets 70. At the outlet of the forming unit 64, a pleated elastic band 66 is thus obtained having the shape shown in FIG. 16 . The forming unit 64 can be configured to form two elastic bands 66 parallel to each other.

In a possible embodiment, the continuous elastic element 68 can be fed between the two wavy non-woven fabric sheets 70 in a non-tensioned state. In this way, at the outlet of the forming unit 64, at least one pleated elastic band 66 is obtained wherein the elastic elements 68 are tension-free. In this case, the at least one elastic band 66 may be fed directly to the anvil wheel 84 without first passing through a slowing device 78.

In a possible embodiment, the continuous elastic element 68 can be fed between the two wavy non-woven fabric sheets 70 in a tensioned state. This can be achieved by operating the feeding device 74 so that it feeds the continuous elastic element 68 at a speed lower than the speed of the two wavy non-woven fabric sheets 70. In this way, at the outlet of the forming unit 64, at least one wavy elastic band 66 is obtained in which the elastic elements 68 are tensioned. This allows obtainment of elastic bands 66 wherein the undulations of the non-woven fabric sheets 70 are particularly compact.

FIG. 17 schematically illustrates a system that makes it possible to obtain two continuous elastic bands 66 starting from a single sheet of non-woven fabric 98. The non-woven fabric sheet 98 is cut in a longitudinal direction so as to form two longitudinal sections 100. On each of the two longitudinal sections 100 a continuous elastic element 68 is applied that can be formed by a plurality of elastic threads 28 parallel to each other or by a laminar elastic film. Each continuous elastic element 68 occupies only one half of the respective longitudinal section 100. Then, each longitudinal section 100 is folded around a longitudinal line 102 so as to enclose the continuous elastic element 68 between two layers of non-woven fabric formed by two overlapping halves of the longitudinal section 100.

The apparatus according to the present invention makes it possible to carry out a continuous cycle production process with a production speed in the order of 800-1000 pieces/1′.

The method and the apparatus according to the present invention allow production of the finished masks without any direct human contact with the products. It is, therefore, possible to pack the masks in sterile packages and ensure the absence of contamination.

Of course, without prejudice to the principle of the invention, the details of construction and the embodiments can be widely varied with respect to those described and illustrated, without thereby departing from the scope of the invention as defined by the claims that follow. 

1. A face protection mask, comprising: a mask body having a longitudinal axis and two side edges, at least one elastic band parallel to said longitudinal axis and having opposite ends fixed to respective side edges of the mask body, wherein said at least one elastic band comprises at least one elastic element trapped between two layers of non-woven fabric, wherein said at least one elastic band comprises a plurality of elastic threads and wherein said two layers of non-woven fabric are welded together by means of a plurality of anchor welds, wherein each anchor weld of said plurality of anchor welds comprises a pair of welds placed at sides of each of said plurality of elastic threads and spaced apart by a length less than a diameter of said an elastic thread of the plurality of elastic threads at rest so as to trap the latter between said two layers of non-woven fabric.
 2. The face protection mask according to claim wherein, in a relaxed condition of the mask body, said at least one elastic band is in a tension-free state.
 3. The face protection mask according to claim 1, wherein said at least one elastic band comprises two elastic bands adjacent to respective longitudinal edges of the mask body and having respective opposite ends fixed to the respective mask body along attachment areas.
 4. The face protection mask according to claim 3, wherein an elastic band of the at least one elastic band has a longitudinal extension at rest which is different from that of another elastic band of the at least one elastic band.
 5. The face protection mask according to claim 4, wherein the attachment areas of a lower elastic band of the at least one elastic band have an extension in a longitudinal direction greater than the extension in the longitudinal direction of the attachment areas of an upper elastic band of the at least one elastic band.
 6. The face protection mask according to claim 1, wherein said layers of non-woven fabric of an elastic band of the at least one elastic band are formed by a single sheet of non-woven fabric folded along a longitudinal line.
 7. A face protection mask, comprising: a mask body having a longitudinal axis and two side edges, at least one elastic band parallel to said longitudinal axis and having opposite ends fixed to respective side edges of the mask body, wherein said at least one elastic band comprises at least one elastic element trapped between two layers of non-woven fabric.
 8. The face protection mask according to claim 7, wherein in an extended condition of the mask body, said at least one elastic band is in a tension-free state.
 9. The face protection mask according to claim 7, wherein said at least one elastic band comprises a plurality of elastic threads.
 10. The face protection mask according to claim 9, wherein said at least one elastic band has said two layers of non-woven fabric welded together by means of a plurality of anchor welds, wherein each of said plurality of anchor welds comprises a pair of welds placed on sides of one of said plurality of elastic threads and spaced apart by a length less than a diameter of said elastic thread at rest so as to trap the latter between said two layers of non-woven fabric.
 11. The face protection mask according to claim 7, wherein said at least one elastic band comprises a laminar elastic element.
 12. The face protection mask according to claim 11, wherein said laminar elastic element comprises a plurality of holes through which said two layers of non-woven fabric are welded together.
 13. The face protection mask according to claim 7, wherein the at least one elastic band comprises two elastic bands adjacent to respective longitudinal edges of the mask bod and having respective opposite ends fixed to the mask body (along respective attachment areas.
 14. The face protection mask according to claim 13, wherein an elastic band of the two elastic bands has a longitudinal extension at rest that is different from that of another elastic band of the two elastic bands.
 15. The face protection mask according to claim 14, wherein the attachment areas of a lower elastic band of the two elastic bands have an extension in a longitudinal direction greater than the extension in the longitudinal direction of the attachment areas of an upper elastic band of the two elastic bands.
 16. The face protection mask according to claim 7, wherein said layers of non-woven fabric of the at least one elastic band are formed by a single sheet of non-woven fabric folded along a longitudinal line.
 17. A face protection mask, comprising: a mask body-having a longitudinal axis and two side edges, at least one elastic band parallel to said longitudinal axis and having opposite ends fixed to respective side edges of the mask body, wherein in an extended condition of the mask body said at least one elastic band is in a tension-free state.
 18. The face protection mask according to claim 17, wherein said at least one elastic band comprises at least one elastic element fixed between two layers of non-woven fabric.
 19. The face protection mask according to claim 18, wherein in an extended condition of the mask body said two layers of non-woven fabric are pleated.
 20. The face protection mask according to claim 17, wherein said at least one elastic band comprises two elastic bands adjacent to respective longitudinal edges of the mask body and having respective opposite ends fixed to the mask body along respective attachment areas adjacent to respective side edges.
 21. A method for producing face protection masks, comprising: forming a succession of mask bodies each having a longitudinal axis-EX) and two side edges, forming a succession of elastic bands, and attaching opposite ends of each elastic band of said succession of elastic bands to respective side edges of a respective mask body of said succession of mask bodies, wherein said elastic bands are fixed to respective mask bodies in a tension-free state.
 22. The method according to claim 21, wherein said elastic bands are fixed to respective mask bodies while the elastic bands advance in a machine direction at a speed greater than a feed rate of the mask bodies in the machine direction.
 23. The method according to claim 21, wherein said elastic bands are pleated when they are fixed to the respective mask bodies.
 24. The method according to claim 21, comprising: forming a continuous sheet having a longitudinal axis, forming at least one continuous elastic band, overlapping said at least one continuous elastic band and said continuous sheet, with said continuous elastic band in a tension-free state, attaching said continuous sheet and said at least one continuous elastic band together in a tension-free state, and cutting said continuous sheet and said at least one continuous elastic band along cutting lines.
 25. An apparatus for producing face protection masks, comprising: a first forming unit configured to form a continuous sheet extending along a longitudinal axis, a second forming unit configured to form at least one continuous elastic band, an anvil wheel on which, in use, said at least one continuous elastic band and said continuous sheet are superimposed on each other, with said at least one continuous elastic band in a tension-free state, a fastening device configured to cooperate with said anvil wheel to fasten said continuous sheet and said at least one continuous elastic band together, and a cutting unit configured for cutting said continuous sheet and said at least one continuous elastic band along cutting lines.
 26. The apparatus according to claim 25, wherein said anvil wheel is configured to advance said at least one continuous elastic band in a machine direction at a speed greater than a feed rate of the continuous sheet in the machine direction.
 27. A method for producing face protection masks, comprising: forming a succession of mask bodies each having a longitudinal axis and two side edges, forming a succession of elastic bands each comprising at least one elastic element trapped between two layers of non-woven fabric, and attaching opposite ends of each elastic band of said succession of elastic bands to respective side edges of a respective mask body of the succession of mask bodies.
 28. The method according to claim 27, wherein said elastic bands are fixed to respective mask bodies in a tension-free state.
 29. The method according to claim 27, wherein said elastic bands are fixed to respective mask bodies while the elastic bands advance in a machine direction at a speed greater than a feed rate of the mask bodies in the machine direction.
 30. The method according to claim 27, wherein two elastic bands of the succession of elastic bands parallel to each other are fixed to each mask body.
 31. The method according to claim 30, wherein lower elastic bands of the two elastic bands are fastened to respective mask bodies on attachment areas having an extension in a longitudinal direction greater than the extension in the longitudinal direction of attachment areas of upper elastic bands of the two elastic bands.
 32. The method according to claim 27, comprising: forming a continuous sheet having the longitudinal axis, forming at least one continuous elastic band comprising a continuous elastic element trapped between two continuous layers of nonwoven fabric, overlapping said at least one continuous elastic band and said continuous sheet, with said at least one continuous elastic band parallel to said longitudinal axis, fixing together said continuous sheet and said at least one continuous elastic band along attachment areas, and cutting said continuous sheet and said at least one continuous elastic band along cutting lines.
 33. The method according to claim 32, wherein the formation of said at least one continuous elastic band involves applying at least one continuous elastic element on a longitudinal portion of a single sheet of non-woven fabric, and folding said single sheet of non-woven fabric along a longitudinal line so as to trap said at least one continuous elastic element between two overlapping longitudinal portions, wherein said two overlapping longitudinal portions correspond to said two continuous layers of non-woven fabric.
 34. The method according to claim 33, wherein said at least one continuous elastic element is fixed between the two layers of non-woven fabric in a longitudinally tensioned state, wherein the at least one continuous elastic band is slowed down before being fixed to said continuous sheet, and wherein the two layers of non-woven fabric comprise two layers of smooth non-woven fabric.
 35. The method according to claim 33, wherein said at least one continuous elastic element is fixed between two layers of non-woven fabric is fixed between two layers of wavy non-woven fabric.
 36. The method according to claim 35, wherein said at least one continuous elastic element is fixed between said layers of wavy non-woven fabric in a tensioned state. 